If Anne Hathaway’s insolent, attention-craving character Kym seems intolerable after only a few scenes, and you begin to question whether you can spend another 100 minutes with her, then screenwriter Jenny Lumet and director Jonathan Demme have you right where they want you. As it happens, there are characters in Rachel Getting Married that are equally dubious about Kym, a recurrent rehab patient who couldn’t care less whether she makes a spectacle of herself at her sister Rachel’s (Rosemarie DeWitt) wedding. Hathaway, breaking from her good girl roles, is so brazen as a chain smoking former drug addict (she’s nine months clean and sober) that the performance at first seems like a transparent, ill-fated attempt to play against type in pursuit of an Oscar nomination. But, thankfully, this film’s formidable cast intervenes. Once Kym is reunited with her family at her father’s home, the site of the weekend’s festivities, she encounters a few opponents who are ready and willing to spar with her, and it’s where Hathaway becomes emotionally dynamic in the role.

Kym feels collective eyes of judgment upon her, whether they’re from her overprotective dad (a sympathetic Bill Irwin) or from Rachel, who is struggling to remain the star of her own wedding and not be eclipsed by Kym’s outspoken defensiveness. When Rachel’s pent-up disdain for Kym’s behavior is unleashed, the tables are turned in Hathaway’s favor. The film relies on a slowly developing empathy for Kym, and DeWitt relieves Hathaway of the burden of carrying the film alone, stealing some scenes from her along the way. DeWitt is the real-life granddaughter of boxer James J. Braddock, who was portrayed by Russell Crowe in Cinderella Man. She has a healthy list of television and theater credits to her name, but she’s a terrific surprise here, this being her most noteworthy film role.

First-time screenwriter Lumet is the daughter of director Sidney Lumet and granddaughter of Lena Horne. The marriage in Rachel Getting Married is an interracial one, with TV on the Radio’s Tunde Adebimpe playing the groom (also named Sidney). But the core of all conflict in the film is between Kym, herself and her family, and has nothing to do with race; the wedding itself is a utopian celebration of multiculturalism and eclecticism, where the music of Neil Young and a samba troupe both are welcomed with smiles.

Demme and director of photography Declan Quinn shot the film handheld on hi-def video without staging or rehearsing, and the results sometimes are reminiscent of the Danish-made films Breaking the Waves, The Celebration and After the Wedding. Because the wedding party in Rachel Getting Married consisted of a number of musicians, Demme chose to use source music throughout the film, which is a Dogme 95 criterion. Still, these are likely coincidences, as Demme is an experienced documentary director. As with the aforementioned films, Demme and Quinn’s method serves the ensemble of actors—which includes Debra Winger as Kym and Rachel’s eerily aloof mom—and ties in to the wedding environment; Demme repeatedly cuts to a guest in a military uniform who is recording the proceedings on his own handheld camera. The spontaneity and interplay among the cast, as events rise and fall from elation to despair, are what give this occasionally affected film its drama and heart.